title: Gray matter parcellation constrained full brain fiber bundling with diffusion tensor imaging.
abstract: OBJECTIVE
  Studying white matter fibers from diffusion tensor imaging (DTI) often requires them to be grouped into bundles that correspond to coherent anatomic structures, particularly bundles that connect cortical/subcortical basic units. However, traditional fiber clustering algorithms usually generate bundles with poor anatomic correspondence as they do not incorporate brain anatomic information into the clustering process. On the other hand, image registration-based bundling methods segment fiber bundles by referring to a coregistered atlas or template with prelabeled anatomic information, but these approaches suffer from the uncertainties introduced from misregistration and fiber tracking errors and thus the resulting bundles usually have poor coherence. In this work, a bundling algorithm is proposed to overcome the above issues.
  
  
  METHODS
  The proposed algorithm combines clustering- and registration-based approaches so that the bundle coherence and the consistency with brain anatomy are simultaneously achieved. Moreover, based on this framework, a groupwise fiber bundling method is further proposed to leverage a group of DTI data for reducing the effect of the uncertainties in a single DTI data set and improving cross-subject bundle consistency.
  
  
  RESULTS
  Using the Montreal Neurological Institute template, the proposed methods are applied to building a full brain bundle network that connects cortical/subcortical basic units. Based on several proposed metrics, the resulting bundles show promising bundle coherence and anatomic consistency as well as improved cross-subject consistency for the groupwise bundling.
  
  
  CONCLUSIONS
  A fiber bundling algorithm has been proposed in this paper to cluster a set of whole brain fibers into coherent bundles that are consistent to the brain anatomy.
authors.affiliation: Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee 37232-2310, USA. qingxu2009@gmail.com
authors.forename: Qing
authors.initials: Q
authors.lastname: Xu
authors.forename: Adam W
authors.initials: AW
authors.lastname: Anderson
authors.forename: John C
authors.initials: JC
authors.lastname: Gore
authors.forename: Zhaohua
authors.initials: Z
authors.lastname: Ding
mesh_terms: D000465:Algorithms; D001921:Brain / Q000166:cytology*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D035501:Uncertainty